I have a 2005 mustang gt with 130k miles, the tail shaft between the manual trans and the driveshaft is leaking, leading the fluid to be low and when the trans heats up it is hard to shift. Which, if any of these, is the right seal to fix the issue im having? Also, the shaft that the drivesahft bolts up to that goes into the transmission on the left side of the first photo, what is that part called and should I replace it, could it be off center and causing a leak? There isn't much...

Transmission seal parts issue